Agriculture Reference
In-Depth Information
treatments in reducing populations of
E. coli
O157:H7 inoculated on apple surfaces,
achieving
3-log reductions. The treatment of strawberries with 5% acetic acid for
1 min reduced populations of
E. coli
O157:H7 by 1.6 log units (Yu and others 2001).
Escudero and others (1999) reviewed the effectiveness of 0.5% acetic and lactic
acid alone and in combination with 100 ppm chlorine and found that the combination
of lactic acid and chlorine was more effective than any either organic acid individually
when tested against
Yersinia enterocolitica
on lettuce. Similar results were reported
by Zhang and Farber (1996) when they reviewed the effectiveness of lactic and acetic
acids alone or in combination with chlorine on
L. monocytogenes
inoculated onto
shredded lettuce.
A commercial citric acid-based product reduced
L. monocytogenes
by 1.0 log CFU/g
when tested at 0.25% for 1 min on shredded lettuce (Hellström and others 2006). These
results were similar to a 100 ppm chlorine wash, which reduced the
Listeria
population
by 0.8 logs. Burnett and others (2004) compared 200 ppm chlorine to a 0.5% citric
acid/surfactant-based product against
L. monocytogenes
on cut lettuce. They reported
both products caused similar reduction in
L. monocytogenes
populations of 1.76 and
1.51 log CFU/piece, respectively. When tested against
E. coli
O157:H7 on shredded
carrots, a different citric acid-based product used at 0.66% was only as effective as
water, providing a 0.79-log reduction over the unwashed control.
The treatment of lettuce with 50 mM of fumaric acid reduced the native fl ora bacte-
rial number by 1.4 logs, which was more effective than 200 ppm sodium hypochlorite;
however, fumaric acid caused browning of the treated lettuce (Kondo and others
2006 ).
>
Conclusion
There are many chemical agents that present viable options to reduce microbial popu-
lations in process water; however, most of these antimicrobials do not eliminate all
pathogens from the surface of produce. A multiple intervention approach throughout
the supply chain must be considered to enhance the safety of fresh and fresh- cut
produce. A better understanding of the interactions among produce, microorganisms,
and antimicrobial agents will provide insight into fi nding means to improve the effi -
cacy of produce washing, including enhancing the contact time of antimicrobials with
pathogens adhered to or entrapped in structures and tissues of fruit and vegetable
surfaces.
References
Adams MR , Hartley AD , Cox LJ . 1989 . Factors affecting the effi cacy of washing procedures used in the
production of prepared salads . Food Microbiology 6 : 69 - 77 .
Aieta E , Berg JD . 1986 . A review of chlorine dioxide in drinking water treatment . Journal of the American
Water Works Association 78 ( 6 ): 62 - 72 .
Al - Haq MI , Seo Y , Oshita S , Kawagoe Y . 2002 . Disinfection effects of electrolyzed oxidizing water on
suppressing fruit rot of pear caused by
Botryosphaeria berengeriana
. Food Research International
35 : 657 - 664 .
Allwood PB , Malik YS , Hedberg CW , Goyal SM . 2004 . Effect of temperature and sanitizers on the survival
of Feline Calicivirus,
Escherichia coli
, and F - Specifi c Coliphage MS2 on leafy salad vegetables. Journal
of Food Protection 67 ( 7 ): 1451 - 1456 .
